Hi, I just finished burning 9 seconds of audio into Session 1 on my CD. Then, 
I tried to use DiscJuggler to burn the image to Session 2 at Mode 2 (CD-XA). 
But, it won't do it! Here's another solution I will try, but I hope someone 
has a better one (a way to convert CDI to ISO would be VERY useful):

1. Burn the CDI image to a CD at MODE 2.
2. Rip the data from the disc to ISO.
3. Burn the ISO to a disc with the audio on session 1.

-- Deven Gallo